The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Different types of tools are used to perform processing operations on substrates such as semiconductor wafers. The processing chambers may be arranged about a central hub. The central hub and the processing chambers may be kept at low pressure.
Substrates may be introduced into the processing chambers by substrate handling systems. The substrate handling systems transfer the substrates from a factory floor to the processing chamber. The substrate handling systems may include load locks to bring the substrates from atmospheric conditions to the low pressure conditions and back. Robots are often used to transfer the substrates. Substrate handling systems may utilize robots that operate at ambient conditions and at low pressure. Throughput, which refers to the number of substrates that are processed in a period of time, is affected by the process time, the number of wafers that are processed at a time, as well as timing of the steps to introduce the wafers into the vacuum processing chambers.